1. Field of the Invention
The present invention relates to a cable connecting mechanism in an electronic apparatus. More particularly, the invention relates to a cable connecting mechanism ideal for a radiation imaging apparatus that records a radiation image.
2. Description of the Related Art
X-ray photography for the purpose of medical diagnosis often makes use of a film screen system that is a combination of an intensifying screen and X-ray photographic film. According to this method, X-rays that have passed through a subject and contain information about the interior of the subject are converted by the intensifying screen to visible light that is proportional to the strength of the X-rays. A radiograph is formed on the X-ray film as a result of photosensitizing the film by the visible light.
Various types of digital imaging apparatus have also come into widespread use in recent years in areas such as the chest ordinarily imaged conventionally using X-ray film, and it is now possible to acquire digital images in the field of diagnostic imagery. For example, a high-resolution digital X-ray detector has been proposed [see the specification of Japanese Patent Application Laid-Open No. 09-021879 (pp. 7 to 11; FIG. 1)]. This digital X-ray detector comprises a two-dimensional array in which 3000 to 4000 detection elements, for example, are arrayed in each dimension. Typically, photodiodes or the like serve as the detection elements. Each detection element produces an electric signal that corresponds to the pixel luminance of the X-ray image projected upon the detector. The signal from each detection element is read out individually and digitized. Image processing is subsequently executed using the digitized data and the processed data is stored and/or displayed.
A portable X-ray digital imaging apparatus (referred to as an “electronic cassette” below) has also been proposed in accordance with certain applications. Such as electronic cassette is desired to be as small and light in weight as possible in consideration of portability and operability. However, the electronic cassette necessitates a large number of components in order to output an X-ray image of a patient as digital image data. For example, the electronic cassette requires a two-dimensional array sensor for receiving the X-rays that have passed through the subject, and a drive circuit for driving the two-dimensional array sensor in accordance with a control signal that is output from an X-ray generator. The electronic cassette further requires an amplifier for selecting a matrix within the two-dimensional array sensor by the drive circuit and amplifying the data of each matrix, an AD circuit for converting the output of the amplifier to digital data, and a circuit for serializing image data that has been digitized successively by the AD circuit and the drive circuit. As a consequence of the foregoing, it is difficult to reduce the size and weight of the electronic cassette in comparison with a film cassette.
Accordingly, a detachable-cable-type electronic cassette has been proposed in order to improve the operability and reduce the size and weight of an electronic cassette [see the specification of Japanese Patent Application Laid-Open No. 11-271454 (pp. 3, 4; FIG. 5)]. Specifically, the reduction in size and weight is achieved by so arranging it that circuitry inclusive of a circuit that transmits data by wire is contained within the electronic cassette. The proposed arrangement is such that when imaging is performed, a cable for supplying power or for communication is connected to the electronic cassette.
However, if the cable is detached unintentionally in such a detachable-cable-type electronic cassette, an error or malfunction may occur in the imaging section depending upon the timing of such cable detachment. In order to avoid such a situation, it has been considered to provide the imaging section or a control panel with a display indicating the state of cable detachability. However, this proposal does not make it possible to prevent the danger that the cable will be detached at an unintended timing due to operator error.